With septic tank facilities, it is important to decrease the quantity of phosphates in septic tank effluent to cut down on the amount of phosphates in water run-off in residential, recreational, and rural areas. A reduction in the amount of phosphates in water run-off substantially decreases the rate of eutrophication in fresh-water areas. By introducing various types of treatment solutions into a septic tank, it is possible by chemical reaction to precipitate the phosphates so as to substantially reduce the quantity of phosphates in the septic tank effluent. The precipitated phosphates remain in the sludge of the septic tank so that a yearly pumping of a septic tank substantially reduces polluting water run-off with phosphates. It is, however, a problem in consistently introducing into the waste liquid a predetermined quantity of treatment solution which is of sufficient concentration to precipitate the expected amount of phosphates in the waste liquid.
Metering pumps could be used to introduce treatment solutions into a septic tank and the like; however, problems are usually encountered due to the corrosive nature of the treatment solutions. For example, alum (aluminum sulphate) is a particularly useful chemical for precipitating phosphates in effluent, however, alum is very corrosive on most types of metal so that a standard type of metallic metering pump could not withstand the handling of alum in dispensing measured quantities of a treatment solution into a septic tank.
It is therefore an object of this invention to provide an apparatus for dosing a treatment solution into a waste liquid which is economical to manufacture, reliable and consistently doses a waste liquid with a predetermined volume of treatment solution.
It is another object of the invention to provide an apparatus for dosing a treatment solution into a waste liquid which includes a device for measuring and dispensing a predetermined volume of treatment solution and control means for determining when waste liquid is present to be dosed and in turn, activate the device to dispense a measured volume of treatment solution into the waste liquid.
It is yet another object of the invention to provide an apparatus for dosing a treatment solution into a waste liquid which is adapted to dose the treatment solution into a septic tank system which is operated under pressure.
It is yet a further object of the invention to provide a venting system for the measuring device used with the apparatus for dosing waste liquid which vents the container of the device during filling and dispensing of treatment solution where the vent means does not permit overflow of the treatment solution to its surroundings.
It is yet another object of the invention to provide a control means with the apparatus which is adapted for connection to a flush toilet to sense when a toilet is flushed to thereby activate a device for measuring and dispensing liquid so that treatment solution is dosed into a waste liquid.
It is a further object of the invention to provide a device for measuring and dispensing a predetermined volume of liquid which is economical to manufacture and is of a construction which resists corrosion in handling various types of corrosive chemicals by the provision of co-acting inlet and outlet diaphragm valves on the device.
It is another object of the invention to provide a reversible actuation means on the device which simultaneously opens or closes the diaphragm valves.